Answer in brief
CVE-2025-39925 records a Unknown severity vulnerability in can: j1939: implement NETDEV_UNREGISTER notification handler. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9d71dd0c70099914fcd063135da3c580865e924c <479d8a2aedcc1db16f14c1a8a9c74b5bdf18b9ac || >=9d71dd0c70099914fcd063135da3c580865e924c <2c88069fac2c792e228e6a4ae71c9b9b5b9a87a6 || >=9d71dd0c70099914fcd063135da3c580865e924c <76957b618ce729c3bd1e782fbc9d9991af653925 || >=9d71dd0c70099914fcd063135da3c580865e924c <4e154cb5e7681c2910e2dfa09f05e3469e333745 || >=9d71dd0c70099914fcd063135da3c580865e924c <da9e8f429139928570407e8f90559b5d46c20262 || >=9d71dd0c70099914fcd063135da3c580865e924c <7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a | 479d8a2aedcc1db16f14c1a8a9c74b5bdf18b9ac, 2c88069fac2c792e228e6a4ae71c9b9b5b9a87a6, 76957b618ce729c3bd1e782fbc9d9991af653925, 4e154cb5e7681c2910e2dfa09f05e3469e333745, da9e8f429139928570407e8f90559b5d46c20262, 7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a |
| Linux/Linuxgeneric | 5.4 | Not reported |
Published upstream
Oct 1, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
In the Linux kernel, the following vulnerability has been resolved: can: j1939: implement NETDEV_UNREGISTER notification handler syzbot is reporting unregister_netdevice: waiting for vcan0 to become free. Usage count = 2 problem, for j1939 protocol did not have NETDEV_UNREGISTER notification handler for undoing changes made by j1939_sk_bind(). Commit 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") expects that a call to j1939_priv_put() can be unconditionally delayed until j1939_sk_sock_destruct() is called. But we need to call j1939_priv_put() against an extra ref held by j1939_sk_bind() call (as a part of undoing changes made by j1939_sk_bind()) as soon as NETDEV_UNREGISTER notification fires (i.e. before j1939_sk_sock_destruct() is called via j1939_sk_release()). Otherwise, the extra ref on "struct j1939_priv" held by j1939_sk_bind() call prevents "struct net_device" from dropping the usage count to 1; making it impossible for unregister_netdevice() to continue. [mkl: remove space in front of label]
Quoted source text, attributed separately from HOL analysis.